Admin UI: Displays dashboard even if Solr is down

Details

Description

1. Run Solr and bruing up the Admin dashboard
2. Stop Solr
3. Click around the Admin GUI. It apparently works, but displays a spinning wheel for most panels
4. Click on "Dashboard". An old cached dashboard is displayed

What should happen is that once connection to Solr is lost, the whole Admin UI displays a large red box "CONNECTION LOST" or something